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By S. C. Sun

A process was developed to recover coal, clays and pyrite from coal wastes. The process consists of fine grinding followed by coal flotation and pyrite flotation leaving the clays in the flotation pulp. A bituminous coal refuse, containing l0% S-30% C*, was treated by this method to yield a coal product containing 4% sulfur, 10% ash; a pyrite product containing 45% sulfur (84% FeS2), 1% carbonaceous material and a clay product containing 2% sulfur (3.5% FeS2). The coal yield was about 89%. The pyrite yield was about 77%. The process steps may be entirely flotation, or gravity separation (hydrocyclone) may be used to increase the pyrite: coal ratio in the flotation feed. Cost estimation shows a profit of $2.28 per ton of low pyrite grade refuse (Labor, maintenance, overhead and plant depreciation were not included). The development of this process consisted of three parts: 1) exploratory tests, 2) optimization tests and 3) confirmatory tests.

Jan 1, 1968

By Lawrence E. Mannion

In southwest Wyoming lies buried the world's largest source of natural sodium carbonate, or soda ash. Perhaps a hundred billion tons of trona (sodium sesquicarbonate) are contained in ancient lake beds in the Green River basin'). There the Green River Formation encloses more than 40 extensive beds of trona. At least 25 of these exceed 3 feet (1 meter) in thickness and most of them are more than 300 square miles in extent. Five have been exposed in mines and lie between 800 and 1500 feet below the surface. Others lie at depths of from 400 to 3500 feet. Three companies have underground mines that supply trona to adjacent soda ash plants. These are the FMC Corporation, Allied Chemical Corporation, and Stauffer Chemical Company. A fourth, Texasgulf Corporation, has a mine under development. In 1974, annual soda ash capacity in the Green River area was approximately 4,300,000 tons, which requires the mining of about 7,500,000 tons of trona.

Jan 1, 1975

By Edwin H. Bentzen

Talc, as a mineral, is rather widespread, but as an ore sultable for mining, it is rather limited. Materials sold as "talc" range from the impeccable white material from Italy to a gray-green-bluish material from Virginia. Some uses of the material called "talc" seem to be determined by the color of the material, some by the chemistry of the material, and some by the particle size of the ground material. But, there seems to be some overlapping of criteria used to judge the acceptability of a raw material. So then, any producer of talc material that is not a consumer of this raw material is faced with the age-old problems: "what do I call the stuff, and to whom should I try to sell it?" The answer to the first part is easy: if you want a high price, call it "talc"; if you want a low price, call it "soapstone". This may seem like a very simplified answer, but it is apparent that some of the products sold as "talc" have more than a minor amount of impurities in them; whereas, if they were called "soapstone", these same products would probably get a lower price.

Jan 1, 1973

By Mark P. Walsh

In recent years in situ leach mining has emerged as a viable technology for the recovery of uranium from strata in South Texas which contain relatively low concentrations of uranium ore. Because the ore bodies lie within groundwater aquifers, a significant determinant in the economics is the requirement that such aquifers be protected from contaminantion. Since ammonia is one of the constituents of the leach solutions now being field tested, one environ- mental problem to be resolved is the removal of ammonia at the end of mining. A second related question is the fate of the ammonia which is not removed by the restoration procedure. This paper considers the displacement and migration of ammonium in a flowing electrolyte with concomitant ion exchange. The ion exchange is an important feature since, during the solution mining phase, ammonium saturates the mineral exchange sites and must be removed from these sites. A mathematical model is used to simulate this process and the model is tested against the results of laboratory experiments. It is found that the simulations are adequate if an appropriate selection of parameters is made. The model is then used to investigate the effect of cation composition and concentration of the restoration medium as well as dispersion on the overall effectiveness of the process. It is concluded that increasing the concentration of monovalent ions in a solution containing a mixture of both monovalent and divalent ions decreases the adsorption selectivity of the divalent ions with respect to all monovalent ions including ammonium. Thus increasing the ionic concentration of a restoration fluid by increasing the concentration of a nonselectively adsorbed (with respect to ammonium) ion may have a very limited benefit. Dispersion attending the flow of fluids in a porous medium is also shown to be an important factor. The effect of dispersion can greatly reduce the benefits of having a displacing cation which is adsorbed selectively with respect to ammonium. Since dispersion increases almost linearly with fluid velocity, an optimum displacement rate may exist.

Jan 1, 1979

By Ranajit Kumar Sahoo, Shatrughan Soren, Surendra Kumar Biswal, Soumya Sahoo, Sachida Nanda Sahu

The presence of appreciable quantity of clay mineral in Indian hematite ore needs an attrition technique using screw scrubber in the beneficiation circuit to remove the ultrafine clays and avoid downstream operational problems. Spectroscopic analysis revealed that iron ore samples obtained from the Barbil region of Odisha contain a high amount of silica and alumina in the form of clay minerals (e.g., kaolinite) contributed as a loss on ignition (LOI) in the iron-making process. Iron ore fines of below 10 mm size were subjected to a laboratory-scale screw scrubber, and the effectiveness of scrubbing as well as the pelletization of the scrubbed product was investigated. The screw scrubber in the beneficiation circuit helps to remove the clay minerals, causes an increase in iron values from 63.65% Fe(T) to 66.18%Fe(T), with improved physical (CCS of 325 kg/pellet) and metallurgical (RDI of 2.24%) pellet properties.

Aug 31, 2020

By K. Burke, K. L. Myers, R. Espell

Barrick's Goldstrike AA heap leach pad is an HDPE-lined facility that was used for gold recovery from low-grade ores using conventional cyanide heap-leach technology. The pad was operated from 1987 through 1999. Goldstrike prepared a unique reclamation plan for the AA leach pad facility to provide for a cost-effective, environmentally sound facility closure and to fulfill the State of Nevada's closure requirements. The traditional Nevada leach pad closure procedure involves rinsing to reduce the cyanide concentration to an acceptable level followed by reclamation. However, rinsing does not typically reduce certain metals and compounds, and some constituents may increase in concentration with rinsing. A closure scenario to effect limited infiltration through installation of a capillary cover for the leach pad was developed. The capillary cover was constructed by placing a fine-grained layer above the coarse-grained spent leach material to create a capillary break. In an arid climate such as in Nevada, the fine-grained layer will rarely reach saturation, and the cover will be able to store water during precipitation events and will allow removal of water through evaporation and transpiration (ET) during the growing season. A 1.22-m (4 ft) cover thickness was selected as the optimum design cover thickness. The drainage network on the surface of the recontoured AA heap leach pad was specifically designed to enhance the re vegetation, reclamation and sediment yield control aspects of the AA heap leach pad closure, while resulting in a natural looking surface that is compatible with the surrounding topography. Adjacent natural topographic features were used to establish target design parameters for recontouring and erosion-control design.

Jan 1, 2002

By M. L. Free

Several studies of the fluorite/oleate flotation system have shown that under certain conditions calcium dioleate is formed at or transported to the fluorite surface. Adsorption of significant amounts of calcium dioleate is generally observed above oleate concentrations of -6 -5 between 4 x 10 and 4 x 10 M, yet little explanation of the onset of calcium dioleate adsorption is provided. In this study in-situ and ex-situ FTIR/IRS experiments have been performed in connection with thermodynamic solution phase analysis to better understand oleate adsorption as well as the onset of calcium dioleate formation. Results from this study are analyzed and compared to industrial practice.

Jan 1, 1995

By Sunny Schoone, Maximilian Getz, Felix Leaman, ELISABETH CLAUSEN

Hydraulic transport is commonly used in mining for moving particles or ore concentrates in pipes over long distances with a water stream. Control and monitoring of this process require sensor technology that can obtain relevant characteristics of the two-phase flow. This work investigates the acoustic emission (AE) technology for monitoring a hydraulic system with different sand concentrations, showing the strong relationship between friction behavior in the pipe and the measured AE signals.

Apr 1, 2023

By AMIT SHARMA, BIBHUTI BHUSAN MANDAL

This paper describes the vibration transmissibility characteristics of mining vehicle seats under dynamic conditions in an opencast iron ore mine. Magnitude and frequency contents of vibration signals on the seat floor as well as on top of the seats were measured to record the change during transmission. The conventional rigid seats were found to resonate at about 4 Hz, which coincides with the resonance of the human spine. The pneumatic suspension seats also proved to be more efficient in attenuating the overall vibration energy transmitted from the vehicle chassis to the human body.

By Anand Kumar, Debasis Deb, A. K. Mishra, M V. N. S. PRASAD.

In the Adriyala project, shield-leg pressure data from all shields and shearer location with time stamp from a mechanized longwall face are monitored and recorded in a surface computer. The data contain random noise due to power failure, leakage of legs, bad sensor readings, and other maintenance or geomechanical problems. An algorithm has been developed to detect mining cycle parameters such as setting and final pressures and duration of the cycle from these data for the analysis of periodic roof weighting phenomena. The intensities and persistence of periodic roof weighting are vital information for mine management to make judicious decisions on longwall operation.

By Robert D. Coale

This paper will describe the copper concentrate slurry pipeline and pumping system between the concentrator and the port at Bougainville Copper Ltd. The operations of Bougainville Copper Ltd. are located on the island of Bougainville in the South Pacific. Geographically, it is the northernmost island of the Solomon Group but, politically, it is part of Papua New Guinea. Papua New Guinea is a United Nations Trust territory administered by Australia, having recently been given self-government, with independence scheduled for December 1974. (Fig. 1). The island is approximately 130 miles long by 30 miles wide, with the Crown Prince mountain range forming a spine along its length. The mountains in place are over 8,000 feet high with the mine located on the western flank at an elevation of 2,200 feet. Exploration on Bougainville for copper by Conzinc Riotinto of Australia (CRA) began in 1963 and by 1968, through geophysical, geochemical and diamond drilling methods, an orebody containing nearly one billion tons of ore grading approximately 0.48% Cu. and sane gold had been outlined. Bougainville Copper Ltd., the company operating the mine, is 53.6% wined by CRA, 20% mined by the government of Papua New Guinea with the public Folding the remainder of the shares. The first copper concentrate was produced in early 1972, with production for the first full year, 1973 being:

Jan 1, 1974

By Robert W. Roscoe

For over a century, St. Joe Minerals Corporation in Southeast Missouri has been sinking shafts for their lead mining operations. Upon discovery of the Viburnum Trend, or "New Lead Belt", St. Joe brought its experience and expertise in shaft sinking to the area. Eleven shafts were then sunk in an 18 year period, ending in 1972. In 1981, St. Joe began sinking a new shaft in the Trend with hand-picked employees from the four operating lead mines and service facilities. The paper describes the general history of St. Joe shaft sinking methods and equipment, focusing on the current development of the Viburnum No. 35 Shaft.

Jan 1, 1983

By Richard H. Olson

Talc deposits in the Precambrian of southwestern Montana (Beaverhead and Madison Counties) are unique within the U. S. A. in that large bodies of tremolite-free talc can be open-pit mined. All known deposits are in pre-Beltian dolomite units. The origin is suspected to be metasomatic, with the siliceous component having been contributed by an intrusive Precambrian granite gneiss. Precambrian deformation was extreme and is characterized by multiple periods of tight isoclinal folding and the flowage of less competent rocks, rather than by faulting. Post- Precambrian folding has been relatively negligible; the characteristic Laramide structure is block-faulting developed along northwest-southeast trends. The talc is thought to have been formed in Precambrian time; the high-angle block-faults probably have no significance with regard to the formation of the talc, but do tend to complicate mining operations. Tremolite-free talc ore bodies with horizontal widths of more than 200 feet, vertical depths of several hundreds of feet, and strike-lengths of as much as one-half mile are known in the Ruby Range and the Gravelly Range. Where dolomite is interbedded with tremolite-free talc in the Gravelly Range, the scale of this relationship permits the use of conventional open-pit mining methods with subsequent upgrading by hand-sorting techniques. Underground mining has been used in the past, but all current Montana talc-mining operations are on the surface. The hand-sorted ore, some of which is shipped overseas, is finely ground or micronized in roller mills and fluid-energy mills. The products are distributed both nationwide and abroad.

Jan 1, 1975

By Chamila Jinendra Nanayakkara, Nimila Dushyantha, Amila Sandaruwan Ratnayake, Gayithri Niluka Kuruppu

Rare earth elements (REEs) are key ingredients in many advanced materials used in energy, military, transportation, and communication applications. However, the prevailing geopolitical dynamics and the rising demand for REEs have rendered the reliance on primary REE resources susceptible to future supply disruptions, posing a substantial risk to the availability of these elements for numerous applications. Therefore, it is imperative to undertake substantial initiatives in the extraction of REEs from secondary sources on a large scale to ensure the resilience of the supply chain. Permanent magnets, lighting phosphors, and nickel-metal hydride (NiMH) batteries are among the secondary sources with high potential for sustainable REE extraction. This review assesses the extraction potential of REEs from the aforementioned three secondary sources and their leaching kinetics and thermodynamics aspects. More importantly, state-of-the-art different existing kinetic models employed in rare earth (RE) leaching were well discussed for a better understanding of the REE leaching reactions. Furthermore, the optimized leaching parameters related to this kinetics were described, and various RE recovery methods were comprehensively summarized. These processes facilitate to managing one of the fastest-growing solid waste streams by minimizing environmental impacts and producing critical metals, including REEs via circular economy approaches. The recovery of REEs from secondary sources aligns with numerous United Nations Sustainable Development Goals (SDGs), particularly in the renewable energy sector for climate change mitigation. Consequently, this trash-to-treasure urban mining concept to transforming e-waste into a valuable resource for REE recovery emerges as a pivotal element within the REE industry.

Dec 28, 2023

By T. J. Smolik

The Golden Sunlight Mine started full-scale operations in February 1983, with a conventional open-pit mine supplying 4464 tonnes (5000 tons) per day of milling ore. After crushing and grinding, the ore is leached with cyanide solution in large agitation tanks. Soluble gold values are removed from the sand portion of the leached ore with five stages of countercurrent washing cyclones. After thickening of the cyclone-wash overflow slurry, the gold is recovered in activated carbon with a six-stage carbon-in-pulp circuit and a five-stage upflow carbon column circuit. Pressure stripping, carbon reactivation, electro-winning and refining complete the gold recovery process.

Jan 1, 1984

By Chris A. Minnucci

In 1978, the U.S. Department of Energy funded a 2-year study to identify and quantify causes of the post-1969 coal mine productivity decline. A large number of factors hypothesized to have affected productivity during this period were analyzed using regression techniques. The results were particularly interesting for two of the factors--mining method and shift scheduling. The study results indicate that the use of longwall mining has an insignificant impact on overall mine productivity, compared to other methods, and mines operating on a two-production shift per day schedule are more productive than mines employing other shift schedules.

Jan 1, 1984

By Wayne A. McCurdy

I welcome the opportunity to meet with you and discuss the work and program of the Office of Coal Research. Our programs are oriented to serve the conservation objectives of the Johnson Administration and of the Nation by seeking out the most efficient and best uses for coal. We believe that even if only a portion of our program is successful, the coal industry and the Nation will benefit far out of proportion to our expenditures. Operating with a budget of $7,220,000 in Fiscal Year 1966, OCR sponsors contract research which offers potential for achieving benefits to the coal industry in the form of new production and new markets. This directs us into many areas of research activity: in coal combustion, in advancements in mining methods and coal preparation, in new uses for coal, and in associated economic and marketing research.

Jan 1, 1966

By R. E. Mason

Shotcrete has been used for approximately 20 years to facilitate tunnel excavation through poor ground. Early examples of such usage in North America include the recuperation of the Granduc Mines access tunnel in Northern British Columbia, and similar work performed in the Carley V. Porter and Big Walker Tunnels in the United States. Mining companies such as Craigmont Mines in B.C. and Hecla Mines have used shotcrete in their workings for the past ten years. Shotcrete is now a widely utilized fool in the mining and tunnel construction industries in North America, but the accumulated experience is too limited for many to fully appreciate the capability of shotcrete to control ground movements and to understand the limitations of this tool. It is common, for instance, to use shotcrete to "bridge the gap" between rock bolt-supported and steel-rib supported ground and to avoid the use of shotcrete in water-bearing ground. Shotcrete can, and has been, used economically and practically under most severe ground conditions.

Jan 1, 1976

By Edward S. Plotkin, Gary A. Almeraris, Thomas F. Peyton

The lining of the tunnel and shafts for a new section of New York City's- water system required extensive components to produce, deliver and place a continuous tunnel linning. The project placed approximately 153,000 CM (200,000 cy) of concrete for 5,340 M (17,520) of drill and blast 7.3 M (24 ft.) ID tunnel, located at depths of 152 M (500 ft.) to 213 M (700 ft.) . This section of tunnel will be connected to the surface water distribution system via four shafts of varying diameters ranging from 5.8 M (19 ft.) ID to 1.5 M (5 ft.) ID . All work was done beneath the streets of Manhattan under the rigid constraints of the City of New York and the Bureau of Water Supply regulations.

Jan 1, 1987

By R. B. Taylor

The Esmeralda mine is located about three miles west of the town of Parral, in the State of Chihuahua, Northern Mexico, and about 400 miles south of El Paso, Texas. The area is serviced by the Interamerican Highway and a branch line of the National Railways of Mexico. The Parral district is quite typical of the semidesert of Northern Mexico, lying near the western margin of the Chihuahua basin and range province known in Mexico as the ?Mesa Central? In the immediate mine area, low rounded hills and rolling plans slope toward the Parral River. Surface elevation at the mine is 5,800 feet. The Esmeralda vein outcrops strongly, but was too low grade to be of interest to the Spaniards, The first claims were staked in 1897 and limited exploration work to a depth of 550 feet was carried out prior to 1912, at which time work was suspended. The Eagle-Picher Company acquired the property in 1944 and by surface diamond drilling outlined an orebody to a depth of 800 feet, Minas de Iguala, S. A, de C.V., one of Eagle-Picher?s totally owned subsidiary companies in Mexico, then unwatered the old workings, developed the mine, installed a modern differential flotation plant and started production lage in 1948. To the present, more than two and ahalf million tons of ore have been mined and milled producing lead and zinc concentrates.

Jan 1, 1958